body {
  // 定义全局变量 - 关注兼容性需求，谨慎使用
  // --black: #333; // 黑色 - 主要字体颜色
  // --gray: #f1f1f1; // 浅灰 - 背景色

  font-family: 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, 'PingFang SC', 'Hiragino Sans GB', 'Heiti SC',
    'WenQuanYi Micro Hei', sans-serif;
  line-height: 1.15;
  background-color: #fff;
  color: #333;
}
a {
  color: inherit;
  text-decoration: none;
}
ul,
p {
  margin: 0;
}
* {
  -webkit-overflow-scrolling: touch;
}

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-thumb {
  background-color: #777;
}

#root {
  .fill;
  font-size: 18px;
  overflow: hidden;
}

.fill {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}

.center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.column {
  display: flex;
  align-items: stretch;
  flex-direction: column;
}

.box {
  .column;
  & > :not(.box-fill) {
    flex-shrink: 0;
  }
  & > .box-fill {
    .column;
    flex: 1;
    position: relative;
  }
}

.page {
  .fill;
  .box;
}

.transition {
  transition: all 0.3s;
}

.loading {
  @keyframes loading {
    0% {
      content: 'Loading';
    }
    25% {
      content: 'Loading.';
    }
    50% {
      content: 'Loading..';
    }
    75% {
      content: 'Loading...';
    }
    100% {
      content: 'Loading';
    }
  }
  &::before {
    content: 'Loading...';
    animation: loading 3s infinite;
  }
}
